Dynamic class name Javascript

Question

I'm looking into creating dynamic objects in Javascript. The way I'd like this to work is similar to new self(); in PHP. Solutions like down here unfortunately didn't solve the problem.

function factory(class_) {
    return new class_();
}

The code sample given is causing me trouble.

import Model from './Model';
var className = 'course';

    class Course extends Model {


        save(success) {
            API.post(className, this.data(), success, function() {
                // notify the user if something went wrong.
            });
        }

        static all(success, failure) {
            API.get(className, (objects) => {
                let all = [];
                for(let object in objects) {
                    let newObject = new Course(objects[object]);
                    all.push(newObject);
                }
                success(all);
            }, failure);
        }

    }

    export default Course;

So to be clear, I'd like Course in let newObject = new Course(objects[object]); to be dynamically assigned.

Instead of typing new Course(); I would like to do something like:

var className = 'Course';

let newObject = new className(objects[object]);

Naturally, this doesn't work. But how could I get it to work?

Thanks in advance!